Narrative history of the U.S. Coast Guard Cryptanalytic Unit
(a.k.a. Unit 387), written by Lt. Leonard T. Jones in October 1943. Describes
the unit’s founding in 1931 by Elizebeth Smith Friedman and its evolution
through Prohibition and into WWII, when the unit was incorporated into Navy
intelligence and renamed OP-20-GU. This history is noteworthy because it
describes in detail the codebreaking work that the Coast Guard did on behalf of
the FBI. It also expresses frustration over the FBI’s "much too free use" of verbatim decrypts provided by the Coast Guard, and criticizes the Bureau's handling of Nazi spies in Brazil during an incident in March 1942.